Liquid pumps may be found in many different types of machines and applications. For example, many vehicles have a liquid pump used to spray water or a detergent solution onto the windshield or head lamps of the vehicle.
Conventional pumps used in such applications typically comprise a pump housing having a circular cross-section, and a liquid outlet tube extending tangential to the housing. The liquid outlet tube typically is cylindrical in shape and has a constant cross-section. However, while a sufficient amount of liquid may be provided through the outlet tube, the pressure of the liquid may be low. In addition, many conventional liquid pumps, when operating at peak efficiency, will typically output more liquid than is required. Therefore, most conventional liquid pumps are not operated at peak efficiency.